Containers, for example, those made with multi-layer materials such as those called Tetra Brick®, which contain liquids, have an opening system composed of a cap, a threaded nozzle glued to the body of the container and, depending on the type, a ring for cutting the breakable sealing membrane. The container is not usually full of liquid, so on opening it for the first time, some air gets inside. This air forms a bag in the upper part that fills with the emptying of the container.
Because of the geometry of the container and of the nozzle, when pouring, and especially in the first few uses, a vacuum forms inside that increases as the container is emptied. There frequently comes a time when the pressure of the vacuum is enough to suck air from the outside and slow down the outflow of the liquid. This results in a new pressure balance, which facilitates the outflow of new liquid. This continuous effect of vacuum and entry of air causes a series of spurts, or discontinuous flows of liquid, and is generally annoying because the liquid often spills and stains the recipient being filled.
The German patent DE202008010645 offers a solution that involves locating a tube in the nozzle that facilitates communication between the air space and the outside. This system requires a change in the manufacture of the containers and to have foreign components in contact with the liquid from the start, so it is not particularly hygienic.
The French patent FR3001205 on an anti-spurt device comprises a tube included in the cap of the container but in this case outside the sealing and closure membrane, so maintaining the hygiene of the contents. The cap comprises a cutting ring that breaks the membrane when the cap is opened for the first time, and in one embodiment drags the tube so that it serves as a ventilation pathway for the container and reduces the spurting in the outflow. In other embodiments, the tube must be manually deployed, with the hygiene problems that this involves and the risk that the tube remains in an incorrect position within the container and fills with liquid. Again, because of the limited dimensions of the tube, its rotation by 180 degrees towards the inside of the container causes interference with half of the teeth of the cutting ring, so these have been removed. This reduced number of teeth may be a serious problem for proper cutting of the sealing membrane.
This system is not very reliable, so it is relatively easy for liquid to get into the tube and to block it. To counter this, there is a small valve in the inner end but there cannot be anything on the outer end. Similarly, the tube is limited in terms of its dimensions, so it only operates appropriately for specific container sizes.
Furthermore, the tube is attached to the nozzle of the recipient and not to the cutting ring, so there is interference with the arms of the cap that drive the cutting ring. Therefore, the assembly and closures that are performed subsequently by users are difficult. Moreover, the tube forces a redesign in the cutting ring, making it more difficult to break the sealing membrane. Also, the join of the tube with the nozzle above the cutting ring limits the height of the cutting ring, so that the teeth and the threading must be small.
When there is no breakable membrane below the nozzle, it is possible to have a tube such as, for example, in the patent GB2345688, but a choice must be made between making it smaller and less practical or making it larger and less manageable.
It is, therefore, necessary to resolve these problems with the French patent, hence the following invention was developed.